Machine for processing sheetlike objects



May l, l951 R. L. MOORE ET AL Y 2,551,332

MACHINE FOR PROCESSING SHEET-LIKE OBJECTS May 1, 1951 R. l.. MOORE ET AL MACHINE FOR PROCESSING SHEET-LIKE OBJECTS 1l Sheets-Sheet 2 Filed Nov. 6, 1947 MQF.

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May l, 1951 R. l.. MOORE ET AL 2,551,332

` MACHINE FOR PROCESSING SHEET-LIKE OBJECTS Filed Nov. 6, 1947 11 SheeoS--Sheerl 5 Fia. 5

f INVENTORS E 2" Rosen 1.. Moana 2,9, 5 25A MAumce HENKIN BY am J s w d/m/Al May l, 1951 R. L. MOORE ETAL MACHINE F'OR PROCESSING SHEET-LIKE OBJECTS l1 Sheets-Sheet 4 Filed NOV. 6, 1947 A BO; 4%/ n 1^ @mi mw N \N\ S m L. n n@ M mm mm m 11 1 M 40 A MS Y @E n M \y .Q UK E Nw E n NQ m I@ MM\ m. IIN vwl J QQ\ f f m n, NRI m HH wm. mm", .S //Y///// x o o o @Af/ /wf mw wm u mw uuu May l, 1951 R. L. MOORE ET AL 2,551,332

MACHINE FOR PROCESSING SHEET-LIKE OBJECTS Filed Nov. 6, 1947 1l Sheets-Sheet 5 37 n l5?? n 57//////57%////\ @2% Q A L lNvENToQs /2/ Roseau' L Moorze MAURICE HENKIN Y BY 'l 1/ May l, 1951 R. MOORE ET AL 2,551,332

MACHINE FOR PROCESSING SHEET-LIKE OBJECTS Filed Nov. 6, 1947 l1 Sheets-Sheet 6 Ff'al/ INVENTRS dZ/ ROBERT L. MOORE May 1, 1951 R. MOORE ETAL 2,551,332

MACHINE FOR PROCESSING SHEET-LIKE OBJECTS Filed Nov. 6, 1947 1l Sheets-Sheet 7 xj l'. LN u I I, I, I, I@ Q- m m N El S Q I I I I E a F I V I I l I P I f a Ix I QS" u I m l` a I "f I Q sw I m E I I NI* I N\ o m O I i E SE] M I I u Q I m* I III m Q Q `EI I I I INI/smoes I Rosen L. Moons I MALI/ICE HENKIN I BVM( J// I f, MW

May 1, 1951 R. L. MOORE ET AL 2,551,332

MACHINE FOR PROCESSING SHEET-LIKE OBJECTS Filed Nov. 6, 1947 ll Sheets-Sheet 8 l A 6M 252A Sqh 262B 263 `Z6B [j /l l 'q ze? 222 ,r i 1 /44 fol I4'5 o@ ilL [53 6 OO H5 [2125 lof E 205 lagig 'I |09 ma?? 260 @2A /f/ 244 @fifi l/ 2'4 3"" r 45 21'? (/552 5 @l5 57 5 2 4 o r 5? XY AZf 207 0216 j "37 Zl' 367 l l 7 55 2/ 7 /1'1 A /74 47K INVENTorzs i 2, ROBERT L Mooze @+23 /75 MAURICE HENKm /Xo `77 all 25 BY )7g /33 M l l n l 4 l l May 1, 1951 R. MOORE ETAL 2,551,332

MACHINE FOR PROCESSING SHEET-LIKE OBJECTS Filed Nov. 6, 1947 11 Sheets-Sheet 9- INVENTOKS ROBERT L. MOORE MAURICE HENKN May l, l951 R. L. MOORE ETAL 2,551,332

MACHINE Foa PROCESSING SHEET-LIKE OBJECTS Filed Nov. e, 1947 11 sheets-Sheet 1o VENTORS L. Moana BY MAURICE HENKIN ma@ May 1, 1951 R. MOORE ET AL 2,551,332

MACHINE FOR PROCESSING SHEET-LIKE OBJECTS Filed NOV. 6, 1947 11 Sheets-Sheet l1 Fie.. 7.9

"l w mvENToRS *l l ROBERT L. Moana 83 f2 MAURICE HENKIN WMM@ E 25 f Patented May 1, 1951 MACHINE FOR PROCESSING SHEETLIKE OBJECTS Robert L. Moore and Maurice Henkin, Memphis, Tenn., assignors to Binswanger Mirror Co., Memphis, Tenn., a corporation of Tennessee Application November 6, 1947, Serial No. 784,402

29 Claims. l

This invention relates to certain new and useful improvements in means and methodsof grinding and polishing bevels on glass sheets, particularly plate glass of the type which is employed in the production of fine mirrors.

From its very beginning the glass industry, and particularly that portion of the industry devoted to the production of mirrors, has been characterized by hand craft methods of processing, and the method of producing bevels on mirrors and other glass surfaces has been an extremely laborious method requiring a multiplicity of separate hand operations.

The present invention primarily relates to a machine for mechanically grinding and polishing straight bevels on glass surfaces such as plate glass mirrors, and to new and novel methods of producing such straight bevels. The present machine is capable of beveling plate glass surfaces in a. minor fraction of the time heretofore required for the hand production of such bevels, and is so constructed as to accurately produce a bevel of precise size and angularity within extremely close tolerances.

The principal object oi the invention is to provide a continuous type straight line production machine :for mechanically grinding and polishing bevels on flat glass surfaces with accuracy and precision.

A further object of the invention is to provide such a machine in which adjustment may be readily made for the production of a bevel of desired depth.

A further object of the invention is to provide such a beveling machine which includes grinding units for removing successive layers of glass from the area to be beveled, and polishing units for polishing the beveled surface thus formed.

A further object of the invention is to provide such a machine in which the grinding units and polishing units may be angularly adjusted in coordination to establish a desired angularity c-f the bevel which is to be imparted to the glass.

A further object of the invention is to provide a machine for beveling plate glass which includes means for conveying the sheets of glass successively to grinding units and polishing units for the application oi bevels thereto.

A further object of the invention is to provide such a machine in which the moving portion ci such conveyor is maintained in a constant plane and the grinding and polishing units are angular-ly adjusted relative to the fixed plane.

A further object of the invention is to provide a machine for beveling plate glass which includes a substantially vertically disposed 1ongitudinally moving conveyor which is adapted to contact a face of the respective sheets of glass to be moved along the machine in which the respective sheets of glass are held against the moving conveyor by substantially horizontally adjustable means.

A further object of the invention is to providea machine for beveling plate glass which includes means for holding the plate glass which are adjustable to compensate for varying thicknesses of sheets of glass to be processed by the machine; and I A further object of the invention is to provide such a plate glass beveling machine and to generally improve the design, efficiency and operation of the beveling processes.

The means by which the foregoing and other objects are accomplished, and the manner of their accomplishment will readily be understood from the following specification upon reference to the accompanying drawings, in which:

Fig. l is a longitudinal front elevational view of the machine of the present invention.

Fig. 2 is a somewhat diagrammatic sectional plan view taken on the line II-II of Fig. 1.

Fig. 3 is a similar view taken on the line III-III of Fig. 1.

Fig. 4 is a fragmentary front elevational view on an enlarged scale showing a portion of the loading section of the machine.

Fig. 5 is a sectional elevation, on a scale similar to the scale of Fig. 4, taken on the line V--V of Figs. 1 and 2 and showing further details of the loading section of the machine.

Fig. 6 is a fragmentary sectional plan view, with certain parts additionally broken away for purposes of illustration, taken on the line VI-VI of Fig. 5 and on a similar scale, showing further details of the loading section and its relation to the grinding section of the machine.

Fig. 7 is a fragmentary sectionalelevation on a further enlarged scale taken on the line VII--VII of Fig. 6.

Fig. 8 is a fragmentary sectional plan view taken on the line VIII-VIII of Fig. '7 and on a similar scale, said Figs. '7 and 8 illustrating details of the mounting and the adjustment means for the pressure rollers of the machine.

Fig. 9 is a sectional elevation on a scale similar to the scale of Fig. 5 taken on the line IX-IX of Figs. 1 and 2 and illustrating a typical crescent bearing member in relation to one of the composite columns of the machine.

Fig. is a front elevational view on a scale slightly smaller than the scale of Fig. 9 of one of the banks of grinders before positioning in the machine.

Fig. 11 is an end view of the bank of grinders shown in Fig. 10.

Fig. 12 is a sectional elevation, on a scale similar to the scale of Fig. 5, taken on the line XII-XII of Figs. 1 and 2 and illustrating details of the grinder banks of the machine.

Fig. 13 is a fragmentary sectional plan View on a similar scale taken on the line XIII-XIII of Fig. 12, and illustrating further details of the grinder section of the machine and its relation to the polisher section.

Fig. 14 is a sectional elevation on the scale of Fig. 5, taken on the line XIV-XIV of Figs. 1 and 2 and illustrating details of the polisher section of the machine.

Fig. 15 is a fragmentary sectional plan view on a similar scale taken on the line XV-XV of Fig. 14, further illustrating details of the polisher section of the machine and its relation to the grinder section.

Fig. 16 is a fragmentary sectional elevation on a further enlarged scale taken on the line XVI-XVI of Fig. 15, and illustrating the details of the controls for the polishers.

Fig. 17 is a fragmentary sectional elevational view on a further enlarged scale taken on the line XVII-XVII of Fig. 16 and illustrating details of the safety switch mechanism of the device.

Fig. 18 is a fragmentary sectional elevation on the scale of Fig. 5, taken on the line XVIII- XVIII of Figs. 1 and 2 and illustrating the details of the controls of the longitudinal table adjustment shaft and the longitudinal angle c ontrol shaft of the invention; and

Fig. 19 is a sectional elevation on a similar scale taken on the line XIX-XIX of Figs. 1 and 2 and illustrating details of the unloading section of the machine.

Referring now to the drawings in which the various parts are indicated by numerals, the machine in general is divided into sections through which the glass being processed is continuously moved in succession, the present preferred form of the machine including a glass feed or loading section Il, a bevel grinding section 3, a bevel polishing section I5, and an unloading or removal section I1.

In the loading section sheets of glass I9 are successively introduced to the machine and are positioned in the substantially upright position which is maintained throughout the movement and processing of the glass by the machine. In the loading section the substantially upright sheets of glass are vertically adjusted to establish the desired depth of the portion which is to be beveled by the machine. The glass is conveyed from the loading section to the grinding section, in which latter section a plurality of grinding wheels are positioned which are disposed to successively remove layers of glass from the glass section to be beveled and to thereby cut the glass section to the size of bevel desired. The movement of the now beveled glass sheets is continuous and passes from the grinding section to the polishing section, in which section the bevel is polished and finished. After the glass has passed through the polishing section and the polishing is thus completed, it is moved to the removal section from which it is taken for storage or further processing if desired.

Each section includes a base, preferably including front and rear channel members 2|, 23 which respectively have their webs vertically disposed and their flanges or legs horizontally disposed and projecting inwardly. A third longitudinal channel member 25 is also preferably included and is disposed with its web horizontal and its legs or flanges projecting downwardly. The forward flange of the member 25 is preferably secured to the inner face of the web of the front longitudinal member 2| intermediate the span of the web, as by welding 25A, so that the longitudinal member 25 projects inwardly from the front channel member and is supported intermediate its ends by its rigid attachment along one fiange to the web of the front channel member. The member 25 spans between and is rigidly secured at its ends as by welding to transverse members 26, which are preferably channel members respectively rigidly secured to the front and rear channel members 2|, 23 and are adapted to tie the longitudinal members together and to furnish end support for the member 25 in each of the sections.

Each section includes a plurality of longitudinally spaced composite columns 21, 28 which are made up preferably from channel members, and each of which includes a rear upright member 29, the lower end of which is seated on and rigidly secured, preferably by welding, to the upper inwardly projecting horizontal flange of the rear channel member 23. The main upright members of the composite columns consist of channel members 3| which are rigidly secured, also preferably by welding, to the horizontally disposed web of the longitudinal members 25 and are disposed at a rearward angle of inclination from the vertical, preferably at an angle of approximately fifteen degrees. The members 3| are of a sufficient length to extend above the upper ends of the rear vertical members 29 and are preferably positioned with their legs or anges projecting rearwardly and the faces of the webs forwardly.

Rigidly secured to the main column members 3| adjacent their upper ends are transverse members 33 which are disposed at right angles to the main column members 3| and extend therefrom rearwardly and on a downward incline of about fifteen degrees from the horizontal to the rear vertical members 29, to the upper ends of which they are rigidly secured, as by welding. The columns preferably include diagonal members 35, also preferably channel members, which are rigidly secured at their lower and rearward ends to the rear vertical members 29 and to the upper flanges of the rear longitudinal members 23 adjacent the junction of these members and extend diagonally upward therefrom to the junction of the main column members 3| with the transverse members 33, to both of which members the diagonal members 35 are preferably secured as by welding. It is believed obvious that the diagonal members provide a strengthening brace for the composite column structure.

In each of the columns 2l the face of the main column member 3| is extended above the transverse column mernbel 33 by a continuation 3|A of the main column member 3|, as illustrated in Fig. 19. In each of the intermediate columns 28 the transverse member 33 is extended forwardly beyond main member 3| by an extension 33A. although extension 33A is preferably omitted from columns 28A, 28B, 28C, and 28D, and the face of the main member is continued by an H Imembers 33.

member section 35, which, as illustrated in Figs. 5', 9, 12 and 14, is seated on and rigidly secured as by welding to the transverse member 33 and extends upward therefrom perpendicular thereto with the face of one of the flanges of the H section in alinement wi h the for-ward face of the main column member 3|. The columns 28 each include a forward vertical member 31, consisting preferably of a channel sectionwhich is seated on and rigidly secured to the horizontal upper flange f a front longitudinal member 2| and extends vertically upward therefrom to an extension 33A of transverse member 33 to which it is preferably rigidly secured as by welding.

The columns 21, 28 include supports l38 whichv are alined with the rearwardly tipped faces of the members 3| of the columns and, which are rigidly secured to and project substantially above the continuations 34A or 35 of the faces of members 3|. The supports 33 are preferably formed of channel sections, of which one'flange lies along and is rigidly secured in alined contact with 'lie respectively rigidly secured as by welding to the forward faces of the supports 38, the angle members 39 being parallel and each having one leg 39A projecting forwardly from the forward face of the supports 38. It will be noted thatthe legs 39A are at right angles to the forward face of the supports 38 and are parallel to the transverse Each angle member journalledly supports a plurality of idler rollers 4|, each said roller being journalled on a spindle 43 which projects upwardly from the leg 39A a'; right angles thereto, the spindles being axially alined so that the rollers are disposed in alinement parallel to the rearwardly tipped forward face of the support 38.

Within the loading section the glass I9 is positioned with its lower edge, which is to be processed by the machine, supported by a conveyor 45 and is tipped rearwardly until the surface of the glass rests against the rollers 4| by which the glass is supported at an angle of inclination from the vertical of approximately fifteen degrees. The conveyor is preferably a table top roller chain 41 driven by sprockets 49 which are coupled in suitable fashion, as by pulley and belt 53 to the main drive of the machine. The sprockets 49 are supported parallel to the rearwardly tipped face of the supports 38 and of the members 33 so as to be similarly tipped rearwardly, to position the glass-supporting up-per flight A of the conveyor at right angles to the rearwardly in the web and parallel to the glass-supporting flightA l 45A of the conveyor.

At its opposite ends the table member has mounted in the web thereof suitable bearings in which are journalled spindles 59 of the sprockets 49 and the respective flanges `lof the table member are cut away as at 55A `adjacent the bearing mountings to eliminate interference with the rotational movement of the sprockets. Intermediate the ends of the table member 55 it is rigidly secured to and supported by internally threaded tubes 6|, which tubes are slidably supported in centrally bored guide members E3, which are respectively secured to the forward face of column member 3| of the columns 21A, 28A with the central bore thereof parallel to the rearwardly inclined face of the column member.

The attachment of the table member to each threaded tube is preferably accomplished by upper and lower blocks 65, 61, the upper blocks 65 being rigidly secured as by welding to the rearof the web of the table member substantially in alinement with the upper face of the upper flange of the table member and being rigidly secured to the tubes 6| above the bored guide members 63. The lower blocks 61 are rigidly secured to the rear face of the tablemember 55 substantially in alinement with the lower face of the lower flange cf the table member and are secured to the tubes 6| below the guide members 63. In this manner 'the blocks 65, 61, in addition to furnishing the I means of attachment between the tubes and the table member, are so disposed as to respectively limit the downward or upward movement of the tubes through the guide members and consequently to limit the movement of the table member.

Rigidly secured to the forward faces of column members 3| below the guide members 63 are bearing blocks 69 which are adapted to turnably support shafts 1| including integral thrust collars 13, each intermediate the length of a related shaft, which collars are adapted to seat respectively on the upper faces of the bearing blocks and support the shaft therein. The shafts each include a threaded portion 15 above the collar 13, and each has a bevel gear 11 keyed to its opposite end and adapted to impart rotation to'the shaft. The threaded portions 15 are adapted to threadedly engage the internally threaded lower portions of the tubes 6| and upon rotation of the shafts 1| by the gears 11, the slidably mounted tubes are advanced or retracted by the threaded engagement. Rotation of the gears 11 is preferably accomplished by a longitudinal shaft 19 and bevel gears 8| secured to the shaft. The shaft 19 preferably extends from end to end of the machine and is supported intermediate. its length by bearings 83 secured to the forward faces of column members 3|. 1

Within the unloading section a substantially identical take-off conveyor 45 is provided, which is similarly adjustably supported by a second longitudinal table member 55 mounted in manner identical with that just above described on additional tubes 6|, supported by columns 21B, 28B, the movement of the tubes 6| being effected by identical threaded shafts 1| throughbevel Ygears 11, rotation of which is effected by bevel gears 8| carried by the shaft 19. In this manner -the conveyors 45 are identically movedI by their and carrying at its inner end a bevel gear 9| which engages an additional bevel gear 93 carried by the upper end of a downwardly projecting shaft 95, suitably supported intermediate its length from the face of the column member 3| and which carries at its lower end a bevel gear 91 positioned to engage an additional bevel gear 99 keyed to the shaft 19, so that upon rotation of the wheel 85, the shaft .91 and gear 9| are turned therewith and effect rotation of the shaft 95 and lower bevel gear 91 through the upper bevel gear 93, and thereby effect rotation of the shaft 19 through the bevel gear 99 secured thereto. As described, rotation of the shaft 19 imparts rotation to the threaded shafts 1|, effecting simultaneous and coordinated adjustment of the tubes 6| which are engaged by the threaded portions 15 of the shafts 1I, and establish desired conveyor level through adjustment of tables 55.

Intermediate the ends of the upper flange of the table members 55 longitudinal conveyor supports IOI, |02 are integrally secured and extend therealong. The conveyor supports are spaced apart to provide a clear passageway for the chain 41 of the table top and respectively abut the lower face of the upper flight 45A of the conveyor to effect support of the conveyor.

Preferably a cover plate |03 is secured at its upper end to the forward conveyor support |I and intermediate its length is secured to the lower flange of the table member 55 and continues therebelow with a depending skirt portion I03A. The skirt portion is of sucient length to overlap the upper edge of a lower cover |05 which is preferably fixed to the upper flange of front longitudinal member 2 I. It will be seen that the cover member |03, being rigidly attached to the table member 55, will move therewith during the adjustment of the position of the table member and the overlapping skirt portion will maintain closure of the junction between the cover plate |03 and the lower cover plate |05.

After the glass I9 has been rested in edge supported position on the loading conveyor 45 and tipped rearwardly to rest against the rollers 4| it is moved by the conveyor toward the grinding section I3. Within the loading section the glass is transferred from the loading conveyor 45 to the main conveyor means by which it is supported and conveyed throughout the processing steps. The moving element of the main conveyor means comprises an articulated endless tread |01 having a forward flight |01A and rearward or return night |01B, these flights being respectively disposed substantially upright and at a rearward angle of inclination of approximately fifteen degrees, the face of the forward flight being alined with the forward edges of the rollers 4| and parallel to the alinement of the glass I9 as initially positioned in the loading section. The tread is preferably made up of plate-like members |01C, of which the outer face is preferably finished with extreme precision in order to establish a base surface for the support of the glass. Each of the plates of the precision tread is preferably covered with a resilient surface, such as the rubber facing |09, which is applied with extreme care as to uniformity and thickness in order to preserve the precision of the base created in the finishing of the respective tread plates.

The coupling of the plates and the drive of the completed tread is accomplished by a roller chain II 0 secured to the rear face of the respective plates. End support and drive of the chain, and consequently of the tread, is accomplished by sprockets III, respectively disposed in the loading and unloading sections of the machine intermediate the length of the respective conveyors 45 and positioned so that the precision tread overlies the rearward portion of the glass-supporting faces 0f the respective conveyors to receive the rearward face of the glass sheets I9 which have been positioned on the loading conveyor 45. The sprockets I|| are mounted on shafts II2, which shafts are preferably journalled in and supported by bridge members spanning between the transverse members 33 of columns 21A, 21C, in the loading section, and of columns 21D, 28C in the unloading section.

Intermediate the sprockets the forward flight of the precision tread is supported by an elongated way |I5 which is preferably rigidly secured to the rearwardly tipped faces of the H member extensions 36 of the respective columns 28. The upper portion of the way preferably includes a forwardly projecting male member I5A which is adapted to cooperate with and slidably fit the longitudinally grooved upper portion |01D of the tread plates and at its lower portion the way I I5 is provided with a forwardly projecting elongated shoulder |I5B extending throughout the length of the way which is adapted to abut and be slidably engaged by a lower shoulder |01E of the tread plates. The upper projection carrying member I5A and the lower shoulder carrying member I|5B are spaced apart to permit the passage therebetween of the roller chain IID of the tread.

Drive of the sprockets I I is preferably accomplished through a chain ||1 and sprocket ||9 coupled in usual fashion to a suitable motor I2I, the sprocket |I9 being mounted preferably on the lower end of the shaft ||2 carrying the sprocket within the unloading section. The drive` of the respective conveyors 45 is synchronized with the drive of the precision tread by the coupling of the respective belts 53, preferably to additional sprockets |20 carried by the upper ends of each of the shafts |I2.

As the loading conveyor 45 moves the glass forwardly, the rear surface of the glass adjacent but above the lower end of the glass is brought into surface contact with the cushion covering |09 of the tread. The opposite or front surface of the glass simultaneously comes into contact with a bank of pressure rollers |2| which serve to clamp the glass rmly against the face of the precision tread. The lower edge of the glass which is to be beveled, indicated at I9A, depends below the pressure rollers |2| and the precision tread |01 and after the glass I9 has passed the end of the loading conveyor 45 the lower edge portion I 9A hangs free for processing by the grinding and polishing units of the machine. It is to be noted that the adjustment of the conveyors 45 is actually relative to the lower edge of the tread |01 so as to establish the length of the depending glass section I9A which is to be processed. The bank of pressure rollers extends throughout the machine between the columns 28C and 28D and the rollers are adjustably mounted to accommodate the desired thickness of the glass I9. The rollers |2| are respectively mounted for rotation in spaced pairs upon spindles |23, the spindles being positioned parallel to and spaced outwardly from the glass contacting face of the tread |01, the opposite ends of the spindles being supported by pressure roller boxes |25. One of the roller boxes is disposed between each pair of columns 28 and each is preferably lincludes an adjustment screw engaging formed of a composite I-beam including parallel upper and lower plates and an intermediate web plate, the upper and lower plates respectively overlying and underlying the upper and lower 1 edges of the web member and being rigidly secured thereto as by welding. Each of the spindles |23 preferably carry a pair of the rollers |2 the rollers |2| being positioned adjacent the ends l of alternate spindles |23 and the rollers of the .remaining spindles |23 being mounted on the spindles spaced from the ends thereof.

Each of the spindles, intermediate the rollers v |2| carried thereby, is adjustably spaced and braced from the web members of the roller boxes through a pressure adjustment assembly which |26 threadedly intermediate its length a suitably threaded aperture in the web member and extending rearwardly into threaded engagement with an internally threaded collar portion |21 of a yoke-like cap |28, the arms of which yoke "embrace the sides of the spindle and prevent lateral movement of the spindle. A compression spring |29, which is adapted to urge the spindle and the rollers carried thereby toward the tread |01, is interposed between the spindle and the threaded collar portion |21 and lies between the yoke arms of the cap member |28. It will be `seen that the compression spring applies pressure to the spindle with which it is associated 'and that adjustment of this pressure to provide 1a yielding brace and establish a desired roller pressure may be accomplished by adjustment of the screw |26. Limited movement of the spindles is permitted by the end mounting of the spindles in the respective upper and lower plates of the yroller boxes, the respective ends being inserted into slots |33 in said members which terminate in forward shoulders |35 limiting movement of the spindles toward the tread |01 and rearward shoulders |31 limiting movement away from the tread, which latter movement is also spring resisted. It will be seen that the adjustment of the pressure of the rollers may be readily effected by tightening or loosening the adjustment screw The roller boxes are rigidly coupled by upper and lower blocks |39, |4| which are of a length to bridge across the respective columns 2B and to effect supporting connection between the respective roller boxes. The web member of each roller box is terminated at each of the columns 28, although the respective upper and lower flanges rearward of the web member may be continued thereacross and cooperate with the upper and lower blocks |39, |4| to effect a stable coupling between the respective boxes. The roller boxes are adjustably supported at the columns 28 by shafts |43 which have their respective inner ends threaded and engaging threaded apertures formed through the upper and lower blocks |39, |4|. Through rotation of the shafts |43 the roller boxes may'be moved `toward or away from the glass contacting face 4*off the tread |01 to effect precise adjustment of the space between the pressure rollers and the face of the tread so as to accommodate a glass sheet of any desired thickness.

The shafts |43 are journalled in bearings |45 carried by gear boxes |41 which are seated on and rigidly secured to the upper faces of forward extensions 33A of transverse members 33 of the columns 28. Within the gear boxes, gears |49 are secured to the ends of the shafts |43 opposite the threaded ends thereof and are enlll gaged for rotation by worm gears |5| carried by an elongated glass thickness control shaft |53, which extends longitudinally of the machine from the column 28C to the column 28D and may be supported in suitable fashion intermediate its length. Rotation of the shaft |53 is preferably effected by a control wheel |55 mounted on the column 28C adjacent the control panel 89 which is preferably secured to a projecting end of the shaft |53. It will be seen that upon rotation of the shaft |53 by the control Wheel |55 the worm gears |5| will be turned thereby and effect rotation of the shafts |43, simultaneously advancing or retracting the blocks |39, |4| dependent upon the direction of rotation of the shaft |53. The roller boxes and the rollers carried thereby are simultaneously advanced or retracted upon the movement of the respective upper and lower blocks. It will thus be seen that the rollers may be positioned with great exactness relative to the glass contacting face of the tread |01 to establish a precise spacing between the rollers and the tread for the introduction of a glass sheet |9 therebetween which is held clamped against the tread face by the pressure mounted rollers.

After the glass has been clamped between the tread and roller elements of the main conveyor with the depending portion |9A of the glass extending below these elements, the glass is moved by the tread out of the loading section and into the grinding section. In the grinding section, grinding wheels |51 are mounted in a plurality of banks, each bank including a plurality of grinding wheels. In the present embodiment of the invention, four banks of grinders, each including three grinding wheels, are illustrated. Each of the banks of grinders is preferably provided with a casing |59, having side walls |60 by means of which casing the bank may be handled as a unit for placing and removal. The side walls |60 of the casings |59 are each provided with an arcuate male bearing member |6| of a crescent bearing, which is adapted to slidably engage an arcuate bearing groove |63 of a bearing mounting |64 mounted on and secured to the face of a column side plate |65, such a plate |65 being attached to the respective sides of the columns 28 in the grinding section and in the polishing section, and being extended upwardly to provide a side housing for the gear boxes |41. The plates |65 are apertured for the passage therethrough of shaft |53, each aperture being preferably provided with a bearing |65A to turnably support the shaft |53 intermediate its length. Each casing |59 is supported for arcuate movement through the cooperation of the male and female bearing members |6I, |63 which are slidably engaged. It is to be noted that the center of the arc of the bearing groove |63 is positioned on the depending glass section |9A at a point which coincides with the base of the bevel to be formed on this section, so that the grinding units are arcuately adjustable relative to the fixed zero point of angularity thus established.

Rigidly secured to and extending longitudinally between the side walls |60 of casings |59 are front baflles |66 which are disposed substantially upright and which are apertured to receive the heads of the grinding wheels |51. Each casing includes table-like base member |61 which is secured to the side walls |60 and along its forward edge is secured to the rearward face of the baffle |66. Below the table members |61 intermediate a'bsnssa longitudinal substantially upright members |68 have their upper edges respectively rigidly secured to the lower faces of the table members and similarly extend between and are secured to the side walls |60 and provide stiffening for the table members. Intermediate the ends of the table members |61 and longitudinal stiifener members |68, projections |69 are secured to the lower faces of the table members and to the rearward faces of the stiffener members, in which projections internally threaded trunnion members |1| are pivotally supported, one such trunnion being provided for each casing |59. The trunnion members |1| are engaged by the rearward threaded ends of elongated screws |13, which extend forwardly and downwardly from the threaded engagement with the trunnions I 1| and are journalled in and project forwardly beyond bearings |14 carried by bearing blocks |15, the bearings being retained in the bearing blocks by suitable bearing caps |16. On the forwardly projecting end of each screw member, a bevel gear |11 is fixed to the unthreaded portion of the screw and the gears |11 are adapted to be engaged by bevel gears |18 carried by an elongated grinding angle control shaft |19. Secured to the opposite sides of the bearing blocks |15 are side plates |80, each side plate preferably including a flange bearing |8| through which the shaft |19 is extended and journalled. The side plates |80 serve as thrust members and serve to retain the screw-carried bevel gears |11 in engagement with the shaft-carried bevel gears |18.

It will be seen that upon rotation of the shaft |19 the threaded screws |13 will, by engagement with the trunnions |1|, cause the raising or lowering of the projections |69 along an arcuate path, moving the casings |59 to desired adjusted position of angularity relative to the glass section |9A. The shaft |19 is supported intermediate its length by suitable bearings |83 which are mounted on the upper horizontal face of longitudinal members 25 and the shaft |19 extends longitudinally of the machine from the control panel 89 through the polishing section and grinding section. Rotation of the shaft is effected by a wheel |85 mounted on a shaft suitably journalled in the control panel 89 and terminating in a bevel gear engaged with the upper bevel gear of a downwardly projecting shaft |81, which shaft |81 carries at its lower end a lower bevel gear |89 which is adapted to engage a bevel gear |9| carried by the shaft |19, so that upon rotation of the wheel |85, rotation of the elongated shaft |19 is effected and consequently the casing angle adjusting rotation of the threaded screws |13.

Each of the grinding wheels |51 is preferably a cup-type grinding wheel having a diamond cutting face, which cutting faces preferably range from very coarse roughers to finishing grinders having considerably finer grit faces. Each of the grinders is preferably independently driven by a motor |93, the motors |93 of each bank preferably being concurrently controlled from a control box |94 conveniently mounted as on the rear face of an H-member 36. Each of the motors |93 is slidably mounted for forward and rearward adjustment upon and supported by the table-like base members |61. The base of each of the motors is preferably secured to a plate |95 which slidably engages blocks |91 secured to the table member |61. Preferably the forward block |91 is internally threaded to be engaged by the threaded end of an adjustment screw |98 which engages the plate |95 so that upon rotation of the screw it is advanced or retracted through the threaded block and moves with it the plate and the motor casing 93 and grinder |51 carried thereby. Identical adjustment mechanisms are preferably provided for each of the grinders, by which adjustment is made to compensate for wear of the grinder faces.

Preferably secured to the side walls |69 and along one edge to the lower edge of the forward face of the baille |68 is a forwardly and upwardly curved basin member |99 which is adapted to serve as a settling basin to retain surplus liquid coolant which may be used in conjunction with the grinders, as hereinafter described. An overfiow pipe 20| extending through and supported by transverse member |68 and opening through the baie |66 into the basin may be provided to prevent excess accumulation of such liquid.

The initial grinder in the grinding section is set to contact the depending glass section ISA and to remove a relatively minor layer of glass therefrom. The remaining grinders are successively incrementally advanced forwardly of the initial grinder to successively contact and remove succeeding layers of glass from the depending section |9A as that section is moved along the grinding section. In this manner the bevel, as desired, is formed to size of the required depth and at the desired angular-ity.

The glass sheet I9 with the bevel thus formed on the depending section IBA is moved by the tread |01 from the grinding section to the polishing section. Within the polishing section, polishers 203 are mounted in a plurality of banks, each bank including a plurality of polishers. In the present embodiment of the invention, three banks of polishers, each including six polishers, are illustrated.

Each of the banks is preferably provided with a casing 359, similar to the casings |59 of the grinders, and by means of which the polisher banks may be each handled as a unit for placing and removal. The side walls 360 of the polisher casings 359 are provided with arcuate male bearing members 36|, identical with the bearing members 6| of the grinder casings, which are adapted to slidably engage the bearing grooves |63 of column plates |65 secured to the columns 28 Within the polishing section, by which the polisher casings are supported for arcuate movement identical and simultaneous with the arcuate adjustment of the grinder casings.

Rigidly secured to and extending longitudinally between the side walls 360 of each casing 359 is a front baille 366 which is disposed substantially upright and which is provided with apertures to receive the heads of the polishers 203. The casings 359 each f-urther include a base plate 361 which at its opposite ends is rigidly secured as by welding to the respective lower edges of the side walls 360 and along its forward edge is similarly secured to the lower edge of the bale 366. Intermediate the ends of the base member 361 and rigidly secured thereto and extending rearwardly therefrom are projections 369, in which projections are pivotally supported internally threaded trunnion members 31| which are similar to the trunnions |1| of the casings |59. Trunnions 31| are engaged by the rearward threaded ends of the elongated screws |13 which are coupled to the shaft |19, in manner identical with that described hereinabove, and illustrated in Fig. 14. Through this arrangement angular adjustment, identical and simultaneous with the angular adjustment of the 13 grinder casings is effected. The polisher casings also preferably include basin members 399 attached to the baffles 366 and end walls 360 and similar to basin members |99 of casings |59.

The polishers 203 of each bank are concurrently driven by a single motor 205 which is connected to a source of power, not shown. The motor is preferably rigidly secured as by bolting to one of the side walls 360 of the polisher casing and drives a motor shaft 201. The motor shaft is preferably coupled by pulleys 209 and belts 2| to an off-set shaft 2|3 which is journalled in suitablel bearings 2|4 secured to the upper face of an intermediate table member 2|5 which is rigidly secured at its forward end to the baille 366, substantially centrally thereof, and is supported at its rear end by an intermediate upright member 2| 6, which is rigidly secured thereto and to the base member 361 as by welding. Each polisher 203 includes a rotatable polishing head 203A, mounted on the forward end of and rotated by a spindle 2|1. On each spindle a pulley 2|8 is mounted, preferably by splining, the respective pulleys 2|8 being arranged in staggered relation. Each of the pulleys 2|8 is coupled by a belt 2|9 to a corresponding pulley 220 mounted on the off-set shaft 2 3, one such pulley 220 being provided for each polisher and spindle. It will be seen that all of the polishers of each bank are driven simultaneously by the motor 205 of that bank, rotation of the spindles 2|1 being concurrently effected and the rotation of polisher heads 203A carried by the spindles 2|1 resulting therefrom.

Each of the spindles 2 1 intermediate its length is journalled in and slidably supported by bearings 22| which are carried -by a hollow quill 223. The quills are slidably supported in suitable apertures formed in transversely spaced longitudinally extending Wall members 225 which extend between and are rigidly secured to the side walls 360 of the polisher casings. Collars 226 are secured to spindles 2|1 rearwardly of the quills 223 and normally spaced a minor distance therefrom.

Adjacent but rearwardly of the polisher heads 203A collars 221 are mounted on the spindles 2|1 and between the collars and the forward bearings 22| compression members, preferably compression springs 229, are interposed and surround the spindles, seating at their forward ends against the collars 221 and at their rearward ends against suitable seat members included in the forward bearings 22|, the springs being interposed under compression.

As shown in Figs. 14, 15 and 16, at least one quill 223A of each polisher bank has a block 23| mounted on and rigidly secured to its upper surface, the upper side of the block being connected to an elongated carriage member 233. This connection is preferably made by screws or other suitably headed members 234 projecting through slots '235 formed in the forward end of the carriage member, which slots are preferably of a length slightly greater than the diameter of the securing member so as to permit limited forward and rearward movement of the carriage member relative to the block 23|. The screws 234 threadedly engage the block in usual manner. The carriage 233 intermediate its length is slidably supported by bracket members 236, 231 which are rigidly secured to and depend from the downwardly facing web of a longitudinal channel member 239 which is rigidly secured at its opposte ends to the side walls 360 of the polisher 14 casing 359. The bracket member 236 extends below the carriage 233 and adjacent its lower end is provided with a bearing 240 in which the spindle 2|1A, associated with quill 223A, is journalled and slidably supported adjacent the pulley 2|8 by which the spindle is rotated, and preferably a similar bracket and bearing is provided for each of the spindles 2 1.

Rearward of the bracket member 231.an arm 24| preferably is pivotally secured, as at 24|A, to the carriage 233, the arm depending from the pivot. The arm 24| adjacent its lower end is provided with a ball member 242 which is mounted in a, forwardly facing recess 243 formed in the arm adjacent the lower end thereof, the ball being preferably retained within the recess by a leaf spring member 244 secured to the forward face of the arm 24| above the recess 243 and provided with a suitable aperture through which a portion of the outer surface of the ball may project. The arm 24| is positioned so that the ball 242 carried thereby normally abuts the rear end of the spindle 2|1A. Rearward of the arm 24| a normally closed type micro-switch 245, having a button control 246, is dependingly supported by an upwardly projecting boss 241 formed in the upper portion of the switch casing, which boss is slidably supported in a slot 248 formed in the carriage member 233 adjacent the rear end thereof. The switch 245 is positioned with the button control 246 abutting and pressed against the rearward face of the arm 24|, the'normally closed switch being held open thereby. The switch is preferably adjustably spaced to maintain its position relative to the arm 24| by a suitable spacing screw carried by a memberV depending from the carriage 233. The slot 248 is preferably substantially oval in shape and of a length slightly in excess of the length of the boss 241 so as to permit limited forward and rearward movement of the boss in the slot.

The undersides of the quills 223 are provided with rack sections 249, engaged by pinions 250 mounted on a longitudinal shaft 25| which is supported intermediate its length byV and is journalled in suitable bearings carried by rewardly projecting bars 252 which are rigidly secured at their forward ends to the forward longitudinal quill supporting wall 225. 'Ifhe shaft 25| is driven through suitable gearing 25|A by a reversible motor 253 which is preferably secured as by bolting to the side wall 260 of the casing opposite that wall upon which the motor 205 is mounted and receives its power from a; suitable source of power, not shown. The motor 253 is 4electrically connected to the micro-switch 245 for control of quill advancing rotationrof shaft 25|.

The springs 229 are normally under compression so as to hold the polishing heads 203A in a constant pressure relation against the bevel of the glass section |9A which is being polished. As the polishing faces of the polishingv heads are worn down during operation, automatic adjustment of the polishers is effected through the means hereinabove described. As the polishing face of a polisher head wears down its spring 229 gradually expands and moves the spindle 2| 1A forwardly, moving the rear end of the spindle out of contact with the ball 242 of the arm 24|, thus relieving the circuit breaking pressure on the button 246 of the switch 245, Upon relief of this pressure the switch closes, completing the circuit and energizing the motor 253 which thereupon effects rotation of the shaft 25| and the pinions 250 which engage the racks 249 and advance the quills 223, recompressing the springs 229. As the quill 223A is moved forwardly the blo .r 23| secured thereto through the screws 234 engages the forward extremities of the slots 235 in the carriage 233, moving the carriage, together with the depending arm 24| and depending switch 245, forwardly within the brackets 235, 231, until circuit breaking contact against the end of the spindle 2|1A is restored, interrupting the quill advancing operation of the motor 253. With the motor 253 stopped the shaft 25| is preferably braked in conventional manner, although such brake is not shown, and the pinions 250 carried by the shaft engaging the racks 249 similarly hold the quills 223 against sliding movement and maintaining fixed rearward seats for the compression springs 229.

A safety switch assembly is preferably included in each polisher bank to interrupt therquill advancing motor circuit through the switch 245 and to complete a motor reversing circuit to the motor 253, in the event of undesired forward overtravel of the polishers 203, either by reason of a failure of the switch 245 or by action of the springs 229 in the event of a gap between succeeding glass plates. This assembly is prefcrably supported by a member 255 which is preferablyvformed of an angle iron having one flange projecting forwardly and its other flange projecting downwardly from the rear edge of the forwardly projecting flange. The forwardly projecting flange is preferably extended through an aperture 256 formed in the front baiile 355 of the casing below the polisher 203, and the downwardly projecting flange is preferably secured to the baille below the aperture.

Mounted on the rearward face of the downwardly projecting flange of the support 255 is a two-position switch 251 having a control button 258. The switch 251 is, in its normal position, wired in circuit with the motor energizing circuit through the switch 245 and upon operation of control 258 is moved out of the rst circuit, interrupting that circuit to its second position in which the switch 251 is adapted to establish a second motor energizing circuit for reverse rotation of the motor 253, such reverse rotation of the motor similarly reversely rotating the shaft 25| and effecting retraction of the polishers.

Positioned in alinement with the button 258 in non-pressing contact therewith is the head of a screw member 259 which is threadedly and adjustably secured in the lower end of a depending member 250 which is rigidly secured at its upper end to a carriage 25|. The carriage is slidably supported in a track member 252 which is mounted on and rigidly secured to the upper face of the angle supporting member 255, with the carriage and track extending through the aperture 255. Preferably the track member 252 is provided with upstanding side portions 252A which 'include inwardly faced elongated raceways 252B in which are mounted bearing balls 253 which engage complementary elongated races 25|A formed in the edges of the carriage. The depending member 250 extends downwardly through a slot 254 formed in the track member 252. At its forward end the carriage 25| carries an upstanding bumper 255 which preferably comprises a rotatably mounted roller. The bumper member is disposed adjacent and spaced minutely forwardly from the lower portion of the 16 head has been advanced into bevel polishing position.

If undesired overtravel of the spindles 2I1 and consequent excessive advancement of the polishing heads 203A occurs, switch 245 closes, the spindle-carried rear collars 225 are advanced substantially into contact with the rear end of the quills and the bumper 265 is contacted by the polisher head, such contact effecting forward movement of the carriage 25| and of the button contacting screw 259. Such movement presses the button control 258 of switch 251 and moves it from the normal switch position, interrupting the circuit through the now closed switch 245 and thereby preventing quill advancing rotation of the motor 253. Such pressure on the button 258 moves it to the second position of the switch and completes the second circuit to the motor 253, energizing the motor for reverse rotation of the shaft 25| and consequent retraction of the quills and the spindles carried thereby.

Retraction of the quills moves them against collars 225 and consequently retracts the polisher heads from the bumper 255, releasing pressure thereon and permitting return movement of carriage 25| relieving pressure on switch control 258, interrupting the reverse rotation of motor 253 and shaft 25|. For the purpose of effecting such return movement of carriage 25|, a tension spring 255 is attached at its forward end to the carriage 25| and extends through a slot 251 formed in the carriage to a suitable securing member, such as a screw 258, by which its rea-rward end is attached to the track member 252. Forward movement of the carriage 25| under polisher pressure on bumper 255 further tenses the spring 265 and upon relief of such polisher pressure by retraction the spring is adapted to return the carriage 25| to its position of original setting. This setting is preferably established and maintained by a spacer screw 259, threadedly engaging a downwardly projecting portion 25|B of carriage 25|, and abutting the forward end of track member 252.

Upon interruption of the reverse motor rotation circuit, by release of the switch control 258 and return of the switch to its normal first position, the quill advancing circuit through closed switch 245 is closed and the quill advanced as before, recompressing springs 229 for further maintenance of bevel contacting pressure by the polisher heads.

Preferably each polishing bank includes a single automatic adjustment actuating mechanism and safety switch mechanism of the type described, but it will be understood that under extreme conditions and whenever desired similar mechanisms may be employed in relation to additional polishers in each bank.

As the glass I9 passes beyond the nal polisher 203 it moves from the polishing section into the unloading section in which the now completed beveled edge of the glass section ISA is brought into edge supported relation with the take-off conveyor 45, which, as described hereinabove, was initially positioned simultaneously with and at the exact level of the loading conveyor 45. As the glass leaves the tread |01 and pressure rollers |2I movement of the glass is continued by the unloading conveyor 45 and the upper portions of the glass are supported against the idler rollers 4| in the unloading section. From this section the beveled glass is removed by an operator and if further bevelling of additional edges periphery of the polishing head 293A when that u of the Aglass is desired it is returned by suitable 17. means to the loading section of the machine and positioned there for additional processing as desired.

Within the unloading section the tread supported way terminates at the column 28C, and for the purpose of supporting the tread in engagement by sprockets ||3, substantially upright idler rollers 210 are journalledly supported in transverse members 21|, for edge engagement of the tread, the members 21| being preferably formed of channel iron or angle iron and being seated on and rigidly secured to the upper face of the transverse member 33 of the column 21D. A supporting frame for the rearward or return flight |01B is provided and extends longitudinally of the machine between the columns 21D and 21C. This frame preferably consists of suitable longitudinally supported members 212 formed as of angle iron and supporting idler rollers 213 which are positioned to contact the face of the tread |01. Edge support of the rearward flight of the tread is preferably furnished by additional idler rollers 215 supported from the frame members 212 and disposed to rollingly con'tact and support the lower edge of the tread.

Means for supporting the tread in sprocket engagement with the sprocket of the loading section is provided by additional idler rollers 210 and transverse members 21| supported from the upper face of the transverse member 33 of the column 21C.

Liquid coolants may be employed with each of the grinders and polishers and, if desired, tanks for containing these liquids may be formed within the base of the machine. Such tanks are not shown in the present illustration of the invention and coolant liquids may be pumped from such tanks or from other sources of supply onto the faces of the grinders and polishers for cooling the glass surface as it is ground and polished, and thereby, if desired, prevent possible damage by overheating to such surface.

The settling basins |99 and 399 are provided to receive the surplus coolant and the glass chips or dust removed from the glass section being processed.

If the use of coolants is desired, splash shields 211 may be employed. One of such shields is preferably provided for each of the polisher banks and grinder banks and are preferably supported at intervals from the way ||5 as by brackets 219. The shields each preferably underlie the way and are provided to prevent undesired splashing of coolant onto the various mechanisms of the machine.

We claim:

1. A machine for processing glass sheets to form a bevel along one edge of said sheets, which includes means for supporting and longitudinally moving successive sheets of glass continuously through said machine in a fixed, substantially upright plane, said means including an endless conveyor at one end of said machine and a sec- 0nd endless conveyor at the opposite end thereof, each said conveyor extending longitudinally along a portion of said machine and having an upwardly facing upper flight disposed substantially at right angles to said plane, adapted to successively receive the respective lower edges of the said glass sheets thereon to support said sheets in said plane for movement in said machine adjacent the ends thereof, an endless tread having a forwardly facing flight parallel to said plane, an elongated integral way supporting said tread flight intermediate the ends thereof, one end of said tread flight overlapping a portion of said upper flight of said first conveyor and the other end of said tread flight overlapping a portion of the upper flight of said second conveyor, said tread flight spanning between and being spaced upwardly equidistant from said upper conveyor flights and being positioned to engage the rearward face of each said glass sheet above the lower edge of said sheet with a section of glass sheet extending below said tread, roller means, means supporting said rollers opposite and parallel to said tread flight to engage the forward face of each said glass sheet and spaced from said tread flight for the entry of said glass theref between, means for moving said roller supporting means toward and away from said tread to adjust said latter spacing to receive said glass sheets, spring means urging said rollers toward said tread to hold said glass sheets against said tread for longitudinal movement of said glass byy said tread, stop means carried by said supporting means limiting spring urged movement of said rollers, means for concurrently raising and lowering said conveyors to vary the said spacing of said tread edge therefrom and establish` the length of the said lower glass sections and means for driving said conveyors and saidv tread in coordination, said flrst conveyor deliveringedge supported glass sheets successively to said spacing between said tread and said rollers for engagement thereby; a plurality of grinders disposed below said tread angularly intersecting the plane of movement of said glass in the path of said lower sections and positioned beyond the end of said rst conveyor ight to successively grindingly contact the said lower sections of said glass sheets moved by said tread adjacent the lower edge of said sections, each succeeding grinder being incrementally advanced forwardly of its pre'- decessor ywhereby to remove successive layers of glass from said lower sections and form bevels thereon, means for rotating said grinders; a plurality of rotating polishers below said tread parallel to said grinders, positioned to polishingly contact the bevels formed by said grinders, means for rotating said polishers; and means for concurrently adjusting the angular position of said polishers and grinders relative to the said plane of said glass; said tread deliveringthe processed said sheets of glass to said second conveyor for movement away from said tread and rollers.

2. A machine for processing glass sheets to form a bevel along one edge of said sheets, which includes means for supporting and longitudinally moving successive sheets of glass continuously through said machine in a fixed, substantially upright plane, said means including an endless conveyor at one end of said machine and a second endless conveyor at the opposite end thereof, each said conveyor extending longitudinally along a portion of said machine and having an upwardly facing upper flight disposed substantially at right angles to said plane, adapted to successively receive the respective lower edges of the said glass sheets thereon to support said sheets in said plane for movement in said machine adjacent the ends thereof, an endless tread having a forwardly facing flight parallel to said plane, an elongated integral way supporting said tread flight intermediate the ends thereof, one end of said tread flight overlapping a portion of said upper flight of said first conveyor, and the other end of said tread flight overlapping a portion of the upper flight of said 'second conveyor, said tread flight spanning between and 

